In my opinion that response was dangerously close to the kind of tone that keeps some folks from posting their opinion.

Hmm. I had thought my tone was completely neutral. If you are referring to the part where I said "balderdash," let me be clear that I was referring to where you were "told by a guy early in our RV experience 'don't drive until you have dumped your blackwater tank because it will form layers of difficult to remove [stuff].'"

Sorry if that wasn't clear and if I came across in any way other than informative. It was not my intent.

In the interests of clarity for anyone reading this after the fact, I have added a phrase to my original response to make my intention more specific.

Based on my experience, I would say this is about as low as you can go for these sorts of things, especially since it is refillable and reusable, and comes with enough "juice" for many uses. Real chemical "smoke pencils" are typically single-use items and come in packages of several units, for considerably more money. You would get them at your local professional plumbing/HVAC supply.

Rick expressed his concern based on how he viewed Sean's comments. Sean responded, including an apology for any offense. That is where it should have stopped.

I have removed posts that went beyond that. I will unlock this thread because it is an apporpriate and beneficial discussion that many have constructively participated in. But more attacks will not be permitted.

Rick expressed his concern based on how he viewed Sean's comments. Sean responded, including an apology for any offense. That is where it should have stopped.

I have removed posts that went beyond that. I will unlock this thread because it is an apporpriate and beneficial discussion that many have constructively participated in. But more attacks will not be permitted.

Any ideas where to get a smoke pencil? It looks like they aren't exactly cheap ($25) and perhaps not easy to find.

I saw some recommendations to use a children's toy instead or incense sticks.

All that you are looking for is something to give you enough smoke to see airflow, that you can move around to find where it's coming from or going to. Incense will work just fine. So will a smoldering cigar or pipe, overheated vegetable oil, etc.